Hi Robin,
Nice work on AZ Cas. indeed difficult area, perhaps also something for my ‘poorman” 😉 debayered DSLR, which has a reasonable QE in the blue area.
Concerning the LHiRES dispersion the native is of course approx. 0.06 Å/px as you can see in the attachment and in a 3x binning absent environment. 😉
Kind regards,
Marc.